Role of AtPol, AtRev1 and AtPol in -ray-induced mutagenesis

線による突然変異誘発におけるAtPol, AtRev1及びAtPolの役割

中川 繭*; 高橋 真哉*; 鳴海 一成; 坂本 綾子

Nakagawa, Mayu*; Takahashi, Shinya*; Narumi, Issei; Sakamoto, Ayako

Ionizing radiations have been applied to plants as useful mutagens, but its molecular mechanism(s) for mutagenesis is less understood. The AtPol, AtRev1 and AtPol are Arabidopsis translesion synthesis (TLS)-type polymerases involved in the UV-induced mutagenesis. To investigate a role(s) of TLS-type DNA polymerases in radiation-induced mutagenesis, we analyzed the mutation frequency in AtPol-, AtRev1- or AtPol-knockout plants, , and , respectively. The mutation frequency in was little changed, whereas the frequency in greatly decreased and in slightly increased compared to that of wild type. Abasic (apurinic/apyrimidinic; AP) site, induced by radiations or generated during DNA repair process, leads to incorporation of any kinds of nucleotides at the opposite strand. The 7,8-dihydro-8-oxo-2'-deoxyguanosine (8-oxo-dG), induced by radiation through the formation of reactive oxygen species, makes pairs with cytosine and adenines. Therefore, AtRev1 possibly inserts dC opposite AP-site or 8-oxo-dG, which results in G to T transversions.